How many graphics cards does my motherboard support?

Question

I have a motherboard with 6 PCI-E sockets and I wanted to know how many graphics cards are supported. The manufactor of the motherboard says that only 3 graphics cards in CrossfireX are supported. I want to place six Sapphire HD6570 graphic cards on my motherboard. Is that possible?

Solution

Crossfire means the cards are run as a single video device, and requires you to link them up - which is chipset dependent and that limit can't be circumvented easily (short of major engineering). You can possibly use 6x video cards for other things though, such as seperate multimonitor or GPGPU type tasks.

There's physical and electrical differences in PCI-E but they're cross compatible - the physical x1 slot is a cut down x16 slot (so you can plug in a x1 device to a x16 connector, though not always vice versa without serious surgery or the better/safer riser option). You can also have a x16 type physical connector running at x8, which often happens with crossfire. When i say connector - i mean physical connector. When i say electrical connection, i mean the bandwith available to it, in terms of x1, x8 and x16. This will probably be clarified to make it less confusing later, when i proofread it ;)

You might be able to run 6x video cards individually as a GPGPU, with some caveats. Firstly, you need a sufficient number of slots of the right physical layout (in your case, most likely a x16 type slot - though there's ways to connect a x16 type connector to a x1 type slot ), and with sufficient bandwidth (you may have some performance loss with a x1 type connector, though apparently modern video cards still may not saturate an x8 type electrical connection). Each video card would be independant (for use as a GPGPU).

Now assuming you're doing the GPGPU thing - you would probably be able to do a layout like this using a mix of x16 slots, and x1 slots with risers - he's used 4 on a older more limited layout but the idea should be sound, and you should be able to test it with a lesser number of cards initially.

Comments

[Indrek]

If the manufacturer says the motherboard only supports up to 3 cards, then that probably means you can't run 6 cards. But if you want to get a definitive answer, you should probably mention your motherboard's make and model.

[lexvdpoel]

gigabyte.co.nl/products/product-page.aspx?pid=3891#ov this motherboar do i use

[lexvdpoel]

oh i maen 5 slots check this oat: gigabyte.co.nl/products/product-page.aspx?pid=3891#ov

[lexvdpoel]

i have 5 pcie 2.0 x16 sockets will tht also work?

[Thalys]

Oh, very likely it should. You might want to clarify your use case too. Point is there's a difference between how many video cards you can use as independant devices, or as part of a crossfire setup.You might get a better answer if you edit your question to include what hardware you are using, motherboard side, and what you intend to use all this video processing power for

[Jeyanth Kumar]

@lexvdpoel read Note 3 and 4 in specification page.. It uses PCEe x16 for two cards and third card goes into PCIe X8

[user5249203]

@lexvdpoel: according to the page you linked your 5 physical x16 slots run at x16, x16, x8, x4, x4.